"Lower water levels concentrate prey and predator. That makes sight feeders more efficient. And, since they're all (smallmouths, spots and largemouths) sight feeders it's about equal there," says Jeff Durniak, Fisheries Supervisor for the Georgia Department of Natural Resources whose region includes Lake Lanier.
"The population goes down a bit but the others get bigger. After that I'd have to say it (the drought and heat) hasn't had a real dramatic effect on smallmouths or spots. It actually may help the largemouth."
The reasons behind his opinion are basic. Smallmouth and spotted bass spawn moderately deep. As such, dropping water levels don't kill their eggs and fry. And, they live in deeper water with access to cooler temperatures. Warm water is mostly an inconvenience to them — something temporary that'll pass with time.
Largemouths, on the other hand, live differently. They need shallow, cover laden water for their spawn, and they actually prefer warmer water. The drought gives them both.
As the lack of rain continues and the heat increases, water levels drop to leave a "bathtub ring" of exposed sediment around the reservoir. This newly exposed soil is rich, so vegetation quickly takes root. Grass and scrub brush sprout within a few days, small pine trees within a few weeks. In short order, everything is covered over.
At the same time, the water that remains in the reservoir clears and allows sunlight to penetrate further than normal. This stimulates aquatic weed growth. The substrate quickly turns into an underwater jungle.
But these conditions don't last forever. At some point the rains return, water levels rise, the shoreline floods and the main lake turns murky. Adult largemouths now have a safe and secure place to build their nests, make babies and hunt forage. And the fry now has a safe and secure place in which to hide while they grow and mature.
"We're seeing some of this in Lanier right now, and we'll probably see more of it in the future. Right now, Lanier is about 20 percent largemouths and 70 or 80 percent spots. With this drought, that may change," says Durniak.
This phenomenon is not limited to Georgia, however. Tennessee saw much the same thing in the 1980s and may see it again.
"We had dry weather then. As the water levels dropped, the water got warm and clear, and the vegetation started growing like crazy. Our spawn recruitment was great and the largemouth bass fishing was phenomenal for several years after that," says Tim Churchill, professional fisheries biologist for the Tennessee Wildlife Resources Agency. "It could happen again."
As good as this sounds, it won't last forever. After a few years the greenery will be gone and the largemouth fishing will slowly return to normal — whatever it was like before the drought.
If these two professionals are right, and history repeats itself, we could be watching a largemouth explosion over the next few years in two of the hardest hit areas of the country. Next week we'll look at how to take advantage of it without permanently damaging the resource.